Alert archive / Michigan / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 152, NWS Indianapolis, IN

August 17, 1987Cass County, Michigan

NWS Indianapolis, IN issued this severe thunderstorm warning at Aug 17, 1987, 12:42 AM EST for Cass County, Michigan. It was in force for 33 min.

The area

The counties it named.

The facts

Issued
Aug 17, 1987, 12:42 AM EST (05:42 UTC)
Expired
Aug 17, 1987, 1:15 AM EST
In force
33 min
Issued by
NWS Indianapolis, IN
Area
Whole counties

County Cass County, MI

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Detroit, MI (KFNT), launched 00:00Z, 5.7 hours before the alert went out and 229 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 00:00Z on 1987-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 00:00Z on 1987-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
144 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1276 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Aug 16, 10:16 PM EST, 2 hours 26 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1015 PM EST SUN AUG 16 1987

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 3AM EST FOR THE
NORTHWEST CORNER OF INDIANA. A SEVERE THUNDERSTORM WATCH MEANS
CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE
TO THE WATCH AREA.

SOME INDIANA CITIES INCLUDED IN THE WATCH ARE...SOUTH BEND...LA PORTE
...RENSSELAER...LAFAYETTE AND VALPARAISO.

SHORTLY AFTER 10 PM EST A LINE OF STRONG TO SEVERE THUNDERSTORMS
EXTENDED FROM NEAR CHICAGO ILLINOIS TO SPRINGFIELD ILLINOIS.
AROUND 930 PM EST SEVERE THUNDERSTORMS WERE REPORTED AT SPRINGFIELD
AND OHARE FIELD WEST OF DOWNTOWN CHICAGO. WIND GUSTS BETWEEN 60 AND
70 MILES AN HOUR HAVE OCCURRED WITH THE SEVERE STORMS.

PERSONS IN NORTHWEST INDIANA SHOULD BE ALERT FOR THESE STRONG STORMS
BETWEEN 11PM AND 3AM EST.  BE PREPARED TO MOVE TO SHELTER QUICKLY IF
SEVERE WEATHER THREATENS YOUR AREA.  FREQUENT CLOUD TO GROUND
LIGHTNING IS A GOOD INDICATOR THAT A STORM MAY BE SEVERE. THESE
STORMS WILL APPROACH FROM THE WEST AT SPEEDS OF 35 TO 40 MILES
AN HOUR.

YOUR BEST SHELTER FROM STRONG WINDS IS IN A STURDY BUILDING ON
THE LOWEST LEVEL...AWAY FROM EXTERIOR WALLS AND WI0NDOWS.
EDWARDS
Special weather statement, Aug 16, 11:15 PM EST, 1 hour 27 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1115 PM EST SUN AUG 16 1987

A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 3AM EST FOR THE
NORTHWEST CORNER OF INDIANA. A SEVERE THUNDERSTORM WATCH MEANS
CONDITIONS ARE FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE
TO THE WATCH AREA.

SOME INDIANA CITIES INCLUDED IN THE WATCH ARE...SOUTH BEND...LA PORTE
...RENSSELAER...LAFAYETTE AND VALPARAISO.

AT 1110 PM EST THUNDERSTORMS WERE ENTERING NORTHWEST INDIANA...ABOUT
25 MILES WEST OF SOUTH BEND. THE STORMS EXTENDED SOUTHWEST TO NEAR
CHAMPAIGN ILLINOIS. A VERY STRONG STORM WAS NEAR GARY INDIANA.

PERSONS IN NORTHWEST INDIANA SHOULD BE PREPARED TO SEEK SHELTER
IF A WARNUING IS ISSUED.

THE STORMS WERE MOVING EAST AT 35 MILES AN HOUR.
EDWARDS

The office that day

Everything else NWS Indianapolis, IN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 11:15 PM ESTSevere Thunderstorm WarningINDBerrien45 min

Nearby

Severe Thunderstorm Warnings in Michigan, 1987Every severe thunderstorm warning in 1987

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.